The present era, with accelerated aging of the population, has an increased need for early diagnosis and treatment of cardiovascular diseases such as heart disease, arteriosclerosis and cerebral apoplexy. For this purpose, there has been a requirement for simple and convenient instrumentation capable of quantitative evaluation of circulatory parameters. Non-invasive measurements which inflict little pain and/or injury are preferable in clinical use. Simultaneous measurement of physiological parameters with the least number of sensing techniques will also be more desirable for screening tests and home care use as well, which will provide an achievement of great social contribution. This research project conducted with such aims to provide a new simple technique for non-invasive and simultaneous physiological measurements based on our innovative sphygmomanometry called "volume-oscillometric(O) and volume-compensation (VC) method" and electrical admittance plethysmography(ADM) proposed pr
… Moreeviously, and following significant results were successfully obtained. (1) A new simultaneous measurement of blood pressure,cardiac output,peripheral vascular resistance,and other important cardiovascular parameters has been proposed in combination of the VO or VC method and the ADM technique. A tetra-polar volume-clamp method has been newly designed for accurate and reliable detection of bio-electrical admittance signal. (2) Arlcrial elastic property in the human limbs has been successfully assessed as a function of blood pressure by measuring quantitavely blood volume changes with an infra-red photo-plethysmography and the ADM technique based on the VO method. (3) A new technique has been designed for the measurement of blood pressure as well as oxygenation of arterial and venous blood using a spectro-photometry based on the VO method. (4) An electrical admittance-cuff method has been newly proposed for the multifunctional and simultaneous measurement of blood pressure, blood flow, arterial and venous elasticity, haematocrit, capillary pressure, capillary filtration coefficient and so on in human limbs. With this method, several physiological findings were non-invasively revealed during exercise testing in terms of regulation of peripheral circulation. (5) Further developments such as long-term ambulatory cardiovascular measurements have been successfully progressed for clinical and home care use, obtaining considerably significant and interesting physiological findings which could not be got by conventional methods. Through these investigations, the present project would serve quite significant contributions in many fields of biomedical engineering, providing a practical multifunctional system for the non-invasive measurement and analysis of cardiovascular haemodynamics.1.無侵襲血圧・血流量計測法:報告者らが以前考案した容積振動法あるいは容積補償法と電気的アドミタンス法とを併用し,血圧と共に血流量を同時計測する方法を新たに提案した。この際,生体アドミタンス信号を高精度に検出する新しいvoltage clamp法を開発し,生体応用計測に世界で初めて成功した。2.無侵襲血圧・血管弾性特性計測法:容積振動法による血圧測定過程で,血管内容積を近赤外光電センサ,あるいはアドミタンス法で定量することにより,血管弾性を血圧の関数で評価する方法を開発し,in vitro及びin vivo試験を通して本法有用性が確認された。3.無侵襲血圧・血液酸素飽和度計測法:2.の光計測で,検出光を2波長分光すれば動・静脈血の酸素飽和度をも分離計測できることを実証し,各種実験的検討から本法精度と有効性が確認され,更に本法が汎用のパルスオキシメトリより優れていることを立証した。4.循環生理情報の多機能同時計測法:以上の研究を発展させ,先ず上記1.に基づく(a)心機能を含む全身循環動態多機能計測法,及び2.に基づき容積定量を高精度で得るアドミタンス・カフ法の考案を通し,(b)体肢末梢循環多機能計測法を新たに提案した。特に(b)では,毛細管圧,毛細管漉過率等の重要な末梢循環機能指標と血液性状をも同時計測できることを実証した。5.無拘束循環動態計測システムと臨床・在宅計測への応用:更に,4-(a)を進展させ,新規の無拘束循環生理計測システムを提案し,臨床及び日常生活下での試用とデータ解析から,従来法では得られない新しい種々の生理学的知見等を見い出した。以上,本研究を通して得られた様々な計測法が,今後多方面の分野に寄与できる基礎が築かれたものと考えられる。 Less